Improvement in railroad-rail joints



T. v. ALLIS.

Railroad Rail-Joints.

No.137,587. Patente.dApril.8,1873.

I '1 5 t n \N W' asses: Inventor:

- 17%w Z Per 2 V Attorneys.

Unrrnn S'ra'rEs PATENT OFFICE.

THOMAS v. ALLIS, or new roan, N. Y.

IMPRCVEMENT IN RAILROAD-RAIL JOINTS.

Specification forming part ofLeiters Patent No. 137,587, dated April 8,1873; application filed February 21, 1873.

To all whom it may concern:

Be it known that I, THOMAS V. ALLIs, of the city, county, and State ofNew York, have invented a new and useful Improvement in Railway-RailJoints, of which the following is a specification:

Steel rails are so liable to fracture by punching that it has been foundnecessary to make the holes for the bolts of fish-joints by boring, sothat the hole made is necessarily round, and as there must be provisionfor the endwise motion of the rail along the bolt caused by expansionand contraction, the hole is of necessity made much larger than thebolt, so that it weakens the rail in its crosssection to a veryconsiderable extent, and more than it would be weakened if, asin ironrails, oblong holes having no greater diameter crosswise of the railthan the bolt could be punched; therefore it is of great importance tocontrive how to lessen the size of the holes and yet preserve thenecessary strength in the bolts, which is the object of my invention,

and which I propose to do by making the holes just the size of theordinary bolt, and then reducing the bolt in size in the part which isin the bolt-hole of the rail when the joint is completed as much as thedepth of the screw-threaded part, making it by so much smaller than thehole, and thus providing for the expansion and contraction, and yet notlessening the strength, of the bolt, because it is still stronger, or atleast as strong, in this reduced part as it is in the threaded part,owing to the deep angular grooves therein, which it is necessary tohave, but

which make that the weakest part of the ordinary bolt, so that thenon-threaded part has greater strength than is available, andconsequently greater size than there is any need of; so that by reducingthis part till it has about the same measure of strength that thethreaded part has I can lessen the bolt-hole in the rail by the samemeasure and have the same strength in the bolt that I would otherwisehave, and thus gain the necessary differment, and Fig. 2 is a horizontalsection taken on the line at a of Fig. 1.

Similar letters of reference indicate corresponding parts.

A represents the rails; B, the fish-plates; O, the threaded portion ofthe bolt; D, a portion of the shank next to the head, which is of thesame size as said threaded part. E is the part between said parts 0 andD, which is reduced to the size calculated to have the same strength asthe threaded part, which, in practice, will, I think, be found a littlesmaller than the diameter between the bottoms of the threads, for thesharp angles at the bottoms of the grooves favor breaking more than asmooth surface does. F is the hole in the rail for the bolt, which isjust large enough to allow the screw'threaded part to pass through. Thepart D of the shank not reduced is that which is in one of thefish-plates, and is left large enough to fill this hole, which must alsobe large enough to pass the screw-threaded part through but this is notmaterial, as the bolt may be reduced throughout the length from thescrew-threads to the head.

While I have described and represented my invention as an improvement inrail-joints, Ido not mean to limit myselfto this particular applicationof it, because it is useful also in the construction of bridges,buildings, and other structures where steel bars or rails are to beconnected so that allowance must be made for expansion and contraction;also, when iron bars or rails are used in which it is preferred to borethe holes instead of punching them.

Having thus described my invention, Iclaim as new and desire to secureby Letters Patent- In arail or other joint in which the rails or barsare subject to expansion and contraction, the holes for the joint-boltsformed of the same size in the crosswise direction of the rails or barsas thethreaded portion of the bolts, and said bolts made as much smallerin the parts which are in said holes as the depth of the grooves of thethread, or thereabout, substantially as specified.

' THOMAS V. ALLIS.

Witnesses:

T. B. MOSHER, ALEX. F. ROBERTS.

